This invention relates to networking and switching systems; and more particularly, this invention relates to distributing traffic destined for a common location among interconnection elements, including interconnection networks, systems, links, and devices and/or other communications mechanisms.
The communications industry is rapidly changing to adjust to emerging technologies and ever increasing customer demand. This customer demand for new applications and increased performance of existing applications is driving communications network and system providers to employ networks and systems having greater speed and capacity (e.g., greater bandwidth). In trying to achieve these goals, a common approach taken by many communications providers is to use packet switching technology. Packet technology typically allows multiple information types to be transmitted over the same transmission lines and using the same packet switching systems and devices.
As used herein, the term xe2x80x9cpacketxe2x80x9d refers to packets of all types, including fixed length cells and variable length packets. Moreover, these packets may contain one or more types of information, including, but not limited to, voice, data, video, and audio information. Furthermore, the term xe2x80x9csystemxe2x80x9d is used generically herein to describe any number of components, packet switch elements, packet switches, networks, computer and/or communication devices or mechanisms, or combinations thereof.
Consumers and designers of these systems typically desire high reliability and increased performance at a reasonable price. A commonly used technique for helping to achieve this goal is for these systems to provide multiple paths between a source and a destination. Packets of information are then dynamically routed and distributed among these multiple paths. It is typically more cost-effective to provide multiple slower rate links or switching paths, than to provide a single higher rate path. Such designs also achieve other desired performance characteristics.
Two commonly used techniques of distributing traffic among the multiple paths between a source and destination are a pure round robin distribution and a pure random distribution. Both of these techniques fail to consider the destination or a downstream point in the network when distributing the traffic. The pure round robin technique repetitively sequences through each of the multiple paths in the same order for traffic without regard to a packet""s destination. The pure random distribution technique randomly selects one of the multiple paths without regard to a packet""s destination. However, such techniques are deficient in their resultant throughput. Desired are improved methods and systems for achieving greater throughput.
According to the invention, systems, apparatus and methods are disclosed for selecting between multiple paths between identified starting and ending points to route a data item. An embodiment of the invention includes a packet switching system, which typically comprises multiple distributors, multiple receivers, and multiple interconnection elements forming multiple paths between each of the multiple distributors and each of the multiple receivers. The distributors select between the multiple interconnection elements to route a particular packet based at least in part on a destination of the packet.